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Poster: LastChance Date: Mar 9, 2006 3:44am
Forum: opensource_movies Subject: How are GIFs generated from MPEG-2 source? Where can I learn about software (custom?) used to run moving pictures archive?

How does IA generate GIFs from the video source files?

Is there any publicly accessible API to help explore IA's contents?

Would IA mind sharing details behind its software solution? Database structure? Anything and everything?

I'm pondering replicating a small set of IA's functionality. I'd love to extend IA's functionality but I assume there are localized coders better suited to the task. Please let me know if there's anyone I can bounce questions off (I assume the Q&A would be best suited to a public space like this forum).

Sorry if this was already covered somewhere and I missed it (please refer me to the info). -lc

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Poster: Madhavananda Date: Apr 23, 2006 4:12am
Forum: opensource_movies Subject: Re: How are GIFs generated from MPEG-2 source? Where can I learn about software (custom?) used to run moving pictures archive?

If you're on Windows and want to easily derive thumbnails at desired intervals, install AviSynth(.Org). If you need to interlace footage, also download LeakKernelDeint and place it in the AviSynth plugin directory.

Then, create a blank text file and rename it to, for example, image-generator.avs. Open in a text editor such as Notepad and paste in the following:


### Which file? Without extension! Also, configure frame settings. ###
ident = "name_of_your_clip"
EverySoManyFrames = 250
StartFrame = 30


### Grab file selectevery (every how many frames, beginning frame) ###
directshowsource(ident + ".mpeg").selectevery(EverySoManyFrames, StartFrame).assumefps(1000)


### If you need to deinterlace, uncomment below. ###
#LeakKernelDeint(0, threshold=15)

converttorgb32()

### If you want to resize, uncomment below. ###
#LanczosResize(640, 480)


### Then, the image generator (create a folder called "images"). ###
ImageWriter ("images/" + ident + "_", type="jpg")

Then, just double click the file or drag it to your media player of choice, and watch the images generated. You can change the image type to PNG or BMP, too, if you want lossless.

This post was modified by Madhavananda on 2006-04-23 11:12:19

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Poster: LastChance Date: Apr 23, 2006 4:21am
Forum: opensource_movies Subject: Re: How are GIFs generated from MPEG-2 source? Where can I learn about software (custom?) used to run moving pictures archive?

Thanks, I'll try that. -Gord

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Poster: Madhavananda Date: Apr 23, 2006 4:24am
Forum: opensource_movies Subject: Re: How are GIFs generated from MPEG-2 source? Where can I learn about software (custom?) used to run moving pictures archive?

I just crunched 12 hours of footage with that, I have 20 more to do. With snaps every 10 seconds, generating 30 minutes of DV footage took about 30 seconds, and XviD compressed took a bit over a minute due to the lag caused by the decompression.

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Poster: Administrator, Curator, or Staffakb Date: Mar 9, 2006 10:05pm
Forum: opensource_movies Subject: Re: How are GIFs generated from MPEG-2 source? Where can I learn about software (custom?) used to run moving pictures archive?

Derivations and thumbnails are created with mplayer and ffmpeg running on linux.

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Poster: richardsur Date: Mar 31, 2006 10:47am
Forum: opensource_movies Subject: Re: How are GIFs generated from MPEG-2 source? Where can I learn about software (custom?) used to run moving pictures archive?

Just look at one of the logfiles to see the exact commandlines used to carry out the tasks. Like the previous poster said, mplayer and ffmpeg are used extensively. But the deriver also uses FAAC to encode the AAC audio, MP4Creator to multiplex the MP4 files, and convert (part of ImageMagick) to generate the animated GIFs.

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